Anyone playing this map in the current SC5 version (5.14) knows that the hostages can't be made to follow the player, thus breaking the map in a very annoying fashion, right at the end when you've already done all the hard work.

The full details are here and the temporary fix is here if you want to manually update your map to this working version.

As AdamR states, the fixed version will be released in the next SC update, but this is an interim solution in the meantime.

* SC 5.15 Update Dec 24, 2017 *
The stock Polar Rescue map shipped with game now includes these fixes.

Though it does still seem to CPU lag my server like crazy when many NPCs and monsters are active, lag due to CPU load dramatically reduces when many monsters are killed off..